Method of treating smoke



C. L. CLARK METHOD OF TREATING SMOKE Aug. 13,- 1957 2 Sheet's-Sfieet 1Filed Doc. 24, 1953 INVENTOR. 0/1 esfer L Clark WW4 WM ATTORNEYS.

Aug. 13,1957 c, (#LARK 2,802,546

METHOD OF TREATING SMOKE Filed Dac. 24, 1953 2 Sheets-Sheet 2 M.- 90INVENTOR.

CHESTER L. CLARK ATTORNEYS FIG. 6

United States Paten 2,802,546 METHOD OF TREATING SMOKE Chester L. Clark,Providence, R. I. Application December 24, 1953, Serial No. 400,237

. 7 Claims. (Cl. 183-120) This invention relates to an improved methodfor eliminating. smoke. More especially it has to do with an improved.method for removing smoke particles and noxious gases from thoseproducts of combustion which customarily are drawn from the place ofcombustion by a chimney, smoke stack. or flue.

In the burning of fuel and rubbish, and particularly in such burningwith devices in which the combustion is not closely controlled, there isusually generated a considerable quantity of smoke particles and noxiousgases. These particles and gases together with heated air must becontinuously withdrawn from the place of combustion and disposed of, buttheir discharge into the atmosphere, as is customary, can be veryoffensive and in some instances dangerous to those in the immediatevicinity. The increasing number of so-called smoke abatement ordinancesrecently established by urban governments serves to further illustratethe desirability of preventing the discharge into the atmosphere of theparticles and gases which offend. The problem has been to providemethods and apparatus which will satisfactorily eliminate smoke and notbe prohibitively expenxsive.

I have discovered that when the smoke is treated in a particular mannerwhich will be more fully described hereinafter a substantial portion ofthe smoke particles may actually be employed to assist in the removal ofthe noxious gases. Thus, the smoke particles are for the most partcarbon and I have found that whensome of these particles are firstcooled and later collected they are capableof adsorbing a portion of thenoxious gases which accompany them and which pass over them at theirplace of collection.

Accordingly, one object of my invention is to effect removal ofparticles from smoke by first cooling and later collecting them and toeffect removal of noxious gases from smoke by exposing them to thesecooled, collected particles whereby those particles which areessentially carbon adsorb the gases.

Another object of my invention is to effect removal of particles andnoxious gases from smoke in the described manner wherein the supply ofparticles capable of ad sorbing noxious gases is constantlybeingreplenished.

Another object of my inventionis to effect removal of particles andnoxious gases from smoke in the described manner wherein the particlescollected are generally small enough in size to permit relatively freepassage of the gases over them when they'are in their collected state.

Another object of this invention is to provide a large surface area ofthe collected carbonaceous particles so that this large surface areawill be exposed to have passed over it additional gases which were theproducts of combustion thatsome of these gases may be absorbed by theexposed solid particles removed from the products of combustion.

With reference to the drawings:

Figure 1 is a sectional view showing diagrammatically the furnace, thesmoke stack leading therefrom and the connections from the furnace to myapparatus and back to the furnace, illustrating in a general way thesystem employed in the invention;

Figure 2 is a perspective view broken away and diagrammatically showingby means of arrows the passage of the smoke and gases through thedifierent areas of the apparatus;

Patented Aug. 13, 1957 ice Figure 3 is a top plan view of the eliminatorplates shown in one of the areas through which the products ofcombustion pass;

Figure 4 is a central sectional view through the first two casings asshown in Figure 2 through which the products of combustion pass;

Figure 5 is a central sectional view through the last two areas ofFigure 2 through which the products of combustion pass;

Figure 6 is a sectional view showing in greater detail the filters whichare utilized and the collection of material in the filter.

The general layout of this invention is perhaps best understood byreference first to Figure 1. The furnace 15a is shown with the fire box16a above the grate 17a which may be loaded through door 18a or beloaded by dropping fuel or refuse from the smoke stack 19 directly intothe fire box. The apparatus Which is primarily the subject of thisinvention is designated generally 20 and receives the smoke from thefire box through conduit 21 to its inlet opening 22, after which itpasses through the apparatus 20, which will be described in greaterdetail hereinafter, and is exhausted through outlet 23 by pump or blower24 to be driven through conduit 26 to the stack 19. A by-pass tube 27extends between conduits 21 and 26 while a fan 28 serves to force gasesthrough the conduit 27 from the conduit 21 to the conduit 26.

With a view of automatically controlling the operation of the apparatus20 so that the same may be shut off when there is no fire in the furnaceand to be placed in operation upon starting a fire in the furnace, theconduit 21 has opposite aligned openings 31 and 32 through the wallsthereof at a location between the furnace and the by-pas's conduit 27 Aphoto tube 29, which is in the electric circuit (not shown) of motorblower 24 and motor fan 28, is positioned opposite one of said openings,as for example opening 31, to receive light rays projecting through saidopenings from an exciter lamp 30 which is positioned opposite the saidopening 32. The photo tube may be shielded (not shown) in an obvious wayto receive only light from lamp 30, which also may have a pro tectingshield (not shown). The photo tube is arranged to control the saidelectric circuit such that when smoke or gas flowing past the saidopenings 31, 32 is sufficiently dense as to block the light of lamp 30from falling on the photo tube, the electric circuit will be closed atthe blower 24 and open at the fan 28. Assuming that no fuel or refuse isbeing burned in the furnace, the light rays of lamp 30 will fall on thephoto tube and actuate the same to close the circuit at the fan 28 toset the same in operation and draw through the by-pass 27 and conduit21, the motor blower 24 being at rest. Upon the furnace being chargedwith refuse and set to burning, sufiicient of the smoke made will bedrawn past openings 31, 32 to by pass 27. Upon such smoke becomingsufficiently dense as to block the light from lamp 30 from falling onthe photo tube 29, the same will be actuated to open the circuit at thefan 28 and close the circuit at the blower 24 to set the same in actionto draw smoke through the apparatus from conduit 21 through inletOpening 22. When the refuse has been completely burned or the smokeflowing through conduit 21 becomes sufficiently clear so as to notrequire passing through the apparatus 20, the light of lamp 30 will fallon photo tube 29 to actuate the same in the other direction to open thecircuit at the mo= tor blower 24 and close the circuit at the fan 28 toreturn the apparatus 20 to the idle condition thereof.

When the blower 24 is in operation, the pressure of the out flow ofgases in conduit 26 will be somewhat in excess of the normal updraft ofsmoke in stack 19 so as to cause but a portion of the gases to bedirected upwardly while another portion is directed downwardly atoneside of the pivoted bafiie 33 as shown by arrow 34 and thus cause adownward circulation and form a block to preventthe gases of combustionin the furnace from being normally pulled up the stack 19 but ratherwill cause. them to circulate through the apparatus 20; Thus, the

stack 19 is left open at all times for the dropping ofrefuse into thefurnace such as down the chute of an apartment house, as shown byarrow'34, although the gases;

forms the function of removing about 75 percent? of the solid mattercontained in the gases passing through the inlet 22, such as removingthe heavy particles of combustion. The drying area serves to remove themoisture or water vapor which has been picked up by the gases duringwashing so as to condition the gases for eflicient filtration, it havingbeen found that gases with considerable moisture in them serve toquickly clog a filter, making filter cleaning frequent. The dryingtherefore links the washing with the filtering so that the filtering maybe performed in the etficient cleaning of the gases. The filteringserves to remove the carbonaceous material which still remains in thegases and to accumulate the carbonaceous material on the filter, and asthis carbonaceous material is prepared for filtering, it is cooled sothat the carbonaceous material, as it builds up on the filter, has acapacity for adsorbing other gases to be filtered and serves to increasethe efiiciency of the apparatus in the removal of other undesirablesolids from the gases.

The washing area of the apparatus 20 consists'of four units 40, 41, 42,and 43, each in the form of a generally rectangular casing with thecasings 40 and 41 in superimposed relation one on the other and with thecasings 42 and 43 in superimposed relation one resting on the other,these two sets of superimposed casings'being side by side with theirwalls contacting as shown in Figure 2 and secured together in anysuitable manner. Connections between .the casings to provide a tortuouspath for the gases are formed by openings in the contacting walls of thecasing so as to secure the desired tortuous path. An'entrance opening 44is provided in the end wall of the casing 40, while openings 45 areprovided adjacent the opposite end of the casing 40. Thus, there will bean opening in the top wall of the casing 40 and in the bottom wall ofthe casing 41 so that gases entering at 44 and passing the length of thecasing 40 will pass upwardly through the contacting walls of these twocasings into the casing 41. An opening 46 is provided in the contactingwalls of casings 41 and 42 so that the gases will thencepass from thecasing 41 to the casing 42 through this opening 46. Thence the gaseswill again be directed longitudinally of the casing 42 and downwardlythrough opening 47 in the contacting walls of the casings 42 and 43 intothe casing 43, thence again longitudinally of the casing 43.

The drying area of the apparatus comprises an additional casing 48,while the filtering area of the apparatus comprises the additionalcasing 49. The casings 48 and 49 are in superimposed relation. These twocasings 48 and 49 are in side by side contact with the casings 42, 43,and for a continued passage of the gases there is an opening 50 in theside walls of the casings 43 and 48 through which the gases pass fromcasing 43 to casing 48, the lower part of this opening being closed byan inclined wall 51 so that the gases pass into the chamber 48 andlongitudinally of this chamber and thence upwardly through opening 52 bymeans of an opening in the top wall of the casing 48 and in the bottomwall of the casing 49 sothat thegases then pass longitudinally of thecasing 49 and out through the'exit opening 53, which will be connectedto the blower and exhaust pipe 26 to the casing having the doors55thereon and generally parallel to the ends of the casing in whichthese doors.

are located. Nozzles 56 are positioned in the end walls of each of thecasings including the casing 40 and in -the doors as at 57, all of whichnozzles are directed longi tudinally of the casing with a flaring sprayso that as the gases enter from conduit 21, they;will be washed inpassing longitudinally of the casing. In the casing 40 where the gasesinitially enter, no*screen is provided, as this would soon becomeclogged because of the heavy particles which are first struck from thegases by the washing spray shown by the dot-dash lines 58. In thesubsequent casings 41, 42, and 43 the streams of water 58 strike thescreen 56 and provide substantially a film of water which is passingdownwardly along the screen at all times so that the gases as they passlongitudinally through the chamber 42 and subsequent chambers 43, 44will pass through this film of water and be washed thereby. Also gaseswill be washed from solid particles in the gases. The water as itcollects upon the bottom wall of the upper casings will pass downwardlyin a sheet 59 through the opening 45 and will provide additional meansofwashing the gases by reason of the sheet of water moving downwardlythrough the openings between the casings. The water as it dropsdownwardly through the opening 61 in the bottom wall of casing 40 entersa trough 60, which extends beneath the casing 43 where it also picks upwater through opening 62 (Fig. 2) and thence continues to discharge thiswater into a tank 63 (Fig. 5) located beneath the casing 48. This tankmaintains the water at a level 64 by means of a float valve 65 and float66 from a supply conduit 67 should water he needed in addition. A pumppicks up the water from a portion of the tank which is screened from thedis charge into the tank 63 and supplies it to the nozzles for washingas shown in Figure 4.

The drying area comprising the casing 48 is of a size to provide anenlarged conduit to slow the passage of the gases that particles ormoisture may more easily drop out. This casing contains a set ofeliminator plates 70 which are shown in greater detail in Figure 3 ascomprising a plurality of tortuous passages formed by plates 72 and 71at angles to' each other, which areprovided with fins 73 and 74 so thatas the washed gases are passed therethrough'in a zig zag path, drops ofwater which may have been picked up by these gases will be caught bythese fins and taken out of the gases. Further, in order to assist inthis drying, an opening 75 (Fig. 5) is provided in one end of the casing48, and'in this opening there is pivoted a damper 76 having a weight 77thereon to move the same to closed position ,but enabling fresh coolerair to be continuously drawn into the casing'48 as 'shown by arrow 78(Fig. 5), whichwill cool these gases and cause moisture which may havebeen picked up by them to more rapidly condenseso that it may be moreeasily removed by the eliminator plates 70. These eliminator plates mayalso'be washed by water being directed upon theiriupper surfaces fromtime to'time. After the gases are dried by passing through theeliminator plates, they pass to the subsequent chamber 49 (Fig. 5) inwhich there are located a plurality of filtersdesign'ated generally '80and consisting of a plurality 'of units, divided by walls 81.: Acommonchannel 82 collects the gases which have just been dried inchamber 48 as they come from the chamber 48. This channel is on one sideof these filters, while a common channel 83 is located on the other sideof these filters and is connected to the outlet opening 53, which inturn connects to the gaseous discharge pipe 23, which in turn connectsto the blower 24 and to the discharge conduit 26.

Each of the filters, a fragmental portion of which is shown in sectionin Figure 6, comprises a supporting wire screen 90 of one half inchmesh. On this screen 90 I place a layer or loose fiberglass in sheetform 91 about one inch thick. A second or dividing wire screen 92 of /2"mesh is placed on the layer of fiberglass, and on this screen I place asecond layer 93 about one inch thick of loose fiberglass which has beenmixed with hydrated lime and lamp black. A second supporting wire screenof k" mesh 94 is placed on the second layer of filtering material so asto support the layer between the screen with a dividing screen 92therebetween to maintain the layers separated and for convenience inbuilding the filter. The screens 90 and 94 are supported between openframes (not shown) which are secured to each other and form the filterunits. The filter units thus formed are six square feet.

To form the one-inch second layer 93, I take about forty pounds of loosefiberglass which is obtained in a loose, lumpy condition, two pounds ofhydrated lime, and one pound of lampblack and machine mix these verythoroughly. The mixing of the loose fiberglass with the lime andlampblack reduces the fiberglass to a porous mass which serves tointercept the small particles of carbonaceous matter designated 95 whichmay have passed through the first layer 91. The lime tends to maintainthe second layer in a rather dry condition to avoid matting. This filtercollects the carbonaceous material 95 which has been cooled and thus hassuch gases as it originally contained driven therefrom. As thecarbonaceous material collects, it provides a somewhat denser filter,and the carbonaceous material serves as an additional filter mediumwhich is in 'a position to filter the gases as they pass therethrough.By reason of the gases being relatively dry by their passage through theeliminator, they do not clog the filter as otherwise would be the caseif the collected particles were in a moist condition, which would enablethem to pack more solidly upon a filter and block it up. Thecarbonaceous material collected, which particles may be globular inshape, provides an extended area which is sufficiently porous for thegases to pass therethrough. This porous 1structure also provides a largesurface area so that the cooled particles from which the gases have beenremoved may serve to adsorb additional gases as they pass over theirsurfaces and thus provide an additional filter to pick up both solidsand gases as the operation progresses. These deposited particles ofcarbon are continually adding to the filter and providing new surfacesfor the adsorbing of additional gases as the process progresses.

I claim:

1. The method of treating smoke for removing unburned matter andobnoxious odors which comprises first passing the smoke betweenoppositely directed sprays of water to wet and knock down the heaviersolid particles of unburned matter, then passing the smoke through aplurality of fine mesh screens While directing opposite sprays of wateron the screens from locations spaced upstream and downstream from theplane of the screens, next inter-mixing the partially cleaned smoke withair at atmosphere to cool and cause condensation of moisture picked up-by the smoke in the washing steps, removing the water condensation fromthe smoke and passing the smoke from which moisture has been takenwithout further wetting through a filter to remove the finer unburnedparticles remaining in the smoke.

2. The method of treating smoke as set forth in claim 1 wherein air atatmosphere is continuously intermixed with the smoke. V

.3. The method of treating smoke as set forth in claim 2 wherein thesprays of water directed on the screens are of sufficient volume to forma continuous moving film of water on the screens.

4. The method of treating smoke for removing unburned matter andobnoxious odors which comprises first passing the smoke through a sprayof water to wet and knock down the heavier solid particles of unburnedmatter, then passing the smoke through a plurality of fine mesh screenswhile directing a spray of water oneach screen, next cooling thepartially cleaned smoke to cause condensation of the moisture picked upby the smoke in the washing steps, removing the water of condensationfrom the smoke and passing the smoke from which moisture has been takenand without further wetting through a filter to remove the finerunburned particles remaining in the smoke.

5. The method of treating smoke for removing unburned matter andobnoxious odors which comprises first passing the smoke through a sprayof water to wet and knock down the heavier solid particles of unburnedmatter, then passing the smoke through a plurality of fine mesh screenswhile directing a spray of water on each screen, next intermixing thepartially cleaned smoke with air at atmosphere to cool and causecondensation of moisture picked up by the smoke in the washing steps,removing the water condensation from the smoke and passing the smokefrom which moisture'has been taken without further Wetting through afilter to remove the finer unburned particles remaining in the smoke.

6. The method of treating smoke for removing unburned matter andobnoxious odors which comprises first passing the smoke betweenoppositely directed sprays of water to wet and knock down the heaviersolid particles of unburned matter, then passing the smoke through aplurality of fine mesh screens while directing opposite sprays of wateron the screens from locations spaced up stream and downstream from theplane of the screens, next cooling the partially cleaned smoke to causecondensation or" the moisture picked up by the smoke in the washingsteps, removing the water of condensation from the smoke and passing thesmoke from which moisture has been taken without further wetting througha filter to remove the finer unburned particles remaining in the smoke.

7. The method of treating smoke and gases originating from combustionwhich comprises washing the larger solid particles from the smoke and atthe same time cooling the gases and the smaller solid particles therein,passing the smoke through a fine mesh screen while directing a spray ofwater on the screen to wash solid particles therefrom, separately andadditionally cooling the gases and smaller solid particles to condensethe water picked up during washing, removing the condensed Water andthen without further wetting collecting the smaller solid particles andpassing additional gases over the collected smaller particles to absorbgases.

References Cited in the file of this patent UNITED STATES PATENTS934,448 Lea Sept. 21, 1909 1,010,068 Pavella Nov. 28, 1911 1,063,320Bayer June 3, 1913 1,382,975 Haslup June 28, 1921 1,577,703 Fedeler Mar.23, 1926 1,651,636 Shaughnessy Dec. 6, 1927 2,207,774 Barthelemy July16, 1940 2,307,292 Palmer Jan. 5, 1943 2,368,828 Hanson et a1. Feb. 6,1945 2,513,174 Hess June 27, 1950 2,585,659 Kilpatrick Feb. 12, 19522,668,754 Lichtenfels Feb. 9, 1954 FOREIGN PATENTS 307,904 Great BritainNov. 21, 1932

